Mucosal immune responses have a central role in the interaction between HIV and man. Sexual transmission of HIV occurs across a mucosal surface and, therefore, mucosal immune cells represent the first line of host defense against the virus. In addition, various mucosal tissues represent sites of viral replication and inflammatory responses that are associated with manifestations of disease. We will, therefore, explore AIDS virus-specific mucosal cellular immune response in the simian immunodeficiency virus (SIV)/rhesus monkey model of AIDS. Specifically we will: 1. Develop techniques for measuring SlV-specific CTL in mucosal tissues in macaque species. 2. Assess the functional repertoire of mucosal CTL in rhesus monkeys during primary and chronic SIVmac infection and compare with systemic CTL. 3. Assess immunogenicity of mucosally administered vaccines and protection conferred by mucosal vaccine-elicited CTL in rhesus monkeys. 4. Assess T lymphocyte immune responses in VLP-immunized monkeys.